I picked up the A26 the other day from an EU supplier - just using the firmware it came with as that suits me fine. It will work with
Blue Iris using RTSP and the PT works too. You can use it with the Smart Tracking enabled (via the LeChange app), but Blue Iris just takes a dumb feed from the camera so it will just follow whatever the camera is tracking. The smart tracking is a little jerky but not too bad for this price. After about a second of no movement it will just return to the position it was in prior to the Smart Track.
Unfortunately the level of customisation is a bit limited - for example I don't think you can turn off the default text overlay (I prefer to let BI take care of timestamps on my other cameras), and at one stage I think BI must have triggered the camera's manual daytime mode so it wouldn't auto switch to Nightime IR mode (and I couldn't find anywhere in the LeChange app to switch mode either). I realised that by activating BI's "Auto IR" button it reactivated the function though so it all appears to be working again now. Presets are called "Favourites" in the LeChange app and I don't think BI can auto detect the names of the presets/favourites, but it gets the positions ok and as you can rename them locally in BI anyway it isn't too much of an issue.
I did notice that the LeChange app seemed to be a bit flakey as to when it would and wouldn't connect to the camera, but that is probably due to my phone trying to connect to my 5GHz network and the camera to the 2.4GHz (I think that is why it struggled to set up the wifi versus the app too - which it seems to do my a series of weird "whoop" sounds). It seems pretty robust though if you use the wired connection for the camera.